1 files changed, 51 insertions, 7 deletions

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index b93ec51fa7ac..a7ac78f8e67a 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -28,6 +28,7 @@ static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
         struct sysfs_dirent *target_sd = NULL;
         struct sysfs_dirent *sd = NULL;
         struct sysfs_addrm_cxt acxt;
+        enum kobj_ns_type ns_type;
         int error;
 
         BUG_ON(!name);
@@ -58,14 +59,29 @@ static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
         if (!sd)
                 goto out_put;
 
+        ns_type = sysfs_ns_type(parent_sd);
+        if (ns_type)
+                sd->s_ns = target->ktype->namespace(target);
         sd->s_symlink.target_sd = target_sd;
         target_sd = NULL;       /* reference is now owned by the symlink */
 
         sysfs_addrm_start(&acxt, parent_sd);
-        if (warn)
-                error = sysfs_add_one(&acxt, sd);
-        else
-                error = __sysfs_add_one(&acxt, sd);
+        /* Symlinks must be between directories with the same ns_type */
+        if (!ns_type ||
+            (ns_type == sysfs_ns_type(sd->s_symlink.target_sd->s_parent))) {
+                if (warn)
+                        error = sysfs_add_one(&acxt, sd);
+                else
+                        error = __sysfs_add_one(&acxt, sd);
+        } else {
+                error = -EINVAL;
+                WARN(1, KERN_WARNING
+                        "sysfs: symlink across ns_types %s/%s -> %s/%s\n",
+                        parent_sd->s_name,
+                        sd->s_name,
+                        sd->s_symlink.target_sd->s_parent->s_name,
+                        sd->s_symlink.target_sd->s_name);
+        }
         sysfs_addrm_finish(&acxt);
 
         if (error)
@@ -107,6 +123,26 @@ int sysfs_create_link_nowarn(struct kobject *kobj, struct kobject *target,
 }
 
 /**
+ *      sysfs_delete_link - remove symlink in object's directory.
+ *      @kobj:  object we're acting for.
+ *      @targ:  object we're pointing to.
+ *      @name:  name of the symlink to remove.
+ *
+ *      Unlike sysfs_remove_link sysfs_delete_link has enough information
+ *      to successfully delete symlinks in tagged directories.
+ */
+void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
+                        const char *name)
+{
+        const void *ns = NULL;
+        spin_lock(&sysfs_assoc_lock);
+        if (targ->sd && sysfs_ns_type(kobj->sd))
+                ns = targ->sd->s_ns;
+        spin_unlock(&sysfs_assoc_lock);
+        sysfs_hash_and_remove(kobj->sd, ns, name);
+}
+
+/**
  *      sysfs_remove_link - remove symlink in object's directory.
  *      @kobj:  object we're acting for.
  *      @name:  name of the symlink to remove.
@@ -121,7 +157,7 @@ void sysfs_remove_link(struct kobject * kobj, const char * name)
         else
                 parent_sd = kobj->sd;
 
-        sysfs_hash_and_remove(parent_sd, name);
+        sysfs_hash_and_remove(parent_sd, NULL, name);
 }
 
 /**
@@ -137,6 +173,7 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
                         const char *old, const char *new)
 {
         struct sysfs_dirent *parent_sd, *sd = NULL;
+        const void *old_ns = NULL, *new_ns = NULL;
         int result;
 
         if (!kobj)
@@ -144,8 +181,11 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
         else
                 parent_sd = kobj->sd;
 
+        if (targ->sd)
+                old_ns = targ->sd->s_ns;
+
         result = -ENOENT;
-        sd = sysfs_get_dirent(parent_sd, old);
+        sd = sysfs_get_dirent(parent_sd, old_ns, old);
         if (!sd)
                 goto out;
 
@@ -155,7 +195,10 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
         if (sd->s_symlink.target_sd->s_dir.kobj != targ)
                 goto out;
 
-        result = sysfs_rename(sd, parent_sd, new);
+        if (sysfs_ns_type(parent_sd))
+                new_ns = targ->ktype->namespace(targ);
+
+        result = sysfs_rename(sd, parent_sd, new_ns, new);
 
 out:
         sysfs_put(sd);
@@ -261,3 +304,4 @@ const struct inode_operations sysfs_symlink_inode_operations = {
 
 EXPORT_SYMBOL_GPL(sysfs_create_link);
 EXPORT_SYMBOL_GPL(sysfs_remove_link);
+EXPORT_SYMBOL_GPL(sysfs_rename_link);